package com.itheima.restkeeper.utils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Random;


/**
 * @Description 登陆验证码工具类
 */
public class LoginAuthCodeUtil {


    /**
     * 随机数字字母
     */
    private static char mapTable[] = {
            'a', 'b', 'c', 'd', 'e', 'h',
            'j', 'k', 'm', 'n', 'p', 'q',
            'r', 's', 't', 'u', 'v', 'w',
            'x', 'y', 'z', '0', '2', '3',
            '4', '5', '6', '7', '8', '9'
    };

    /**
     * <b>方法名：</b>：getCertPic<br>
     * <b>功能说明：</b>：验证码图片<br>
     */
    public static String getCertPic(int width, int height, ByteArrayOutputStream byteArrayOutputStream) {
        if (width <= 0) {
            width = 60;
        }
        if (height <= 0) {
            height = 22;
        }

        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        //获取图形上下文
        Graphics g = image.getGraphics();
        //设定背景颜色
        g.setColor(new Color(0xDCDCDC));
        g.fillRect(0, 0, width, height);
        //画边框
        // g.setColor(Color.black);
//        g.setColor(new Color(2, 67, 121));
//        g.drawRect(0, 0, width-1, height-1);
        //随机产生的验证码
        String strEnsure = "";
        //4代表4位验证码，如果要生成等多位的验证码 ，则加大数值

        for (int i = 0; i < 4; i++) {
            strEnsure += mapTable[(int) (mapTable.length * Math.random())];
        }
        //将验证码显示在图像中，如果要生成更多位的验证码，增加drawString语句
        g.setColor(new Color(0x003399));
        g.setFont(new Font("Atlantic Inline", Font.PLAIN, 18));
        String str = strEnsure.substring(0, 1);
        g.drawString(str, 8, 17);
        str = strEnsure.substring(1, 2);
        g.drawString(str, 20, 15);
        str = strEnsure.substring(2, 3);
        g.drawString(str, 35, 18);
        str = strEnsure.substring(3, 4);
        g.drawString(str, 45, 15);
        //随机产生10个干扰点

        Random random = new Random();
        for (int i = 0; i < 10; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            g.drawOval(x, y, 1, 1);
        }
        //释放图形上下文
        g.dispose();
        try {
            //输出图像到页面
            ImageIO.write(image, "JPEG", byteArrayOutputStream);
            byteArrayOutputStream.flush();
            byteArrayOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return strEnsure;

    }


}
